Wallpaper & Phone Display Tools

A small set of free, no-nonsense tools that run entirely in your browser. They put the ideas from the blog into practice — estimating the battery a dark wallpaper saves, pulling a colour palette out of an image, previewing how a picture sits behind your clock and icons, comparing phone displays, and pointing you at the theme that fits you. Nothing is uploaded to a server; any image you pick is processed on your own device and never leaves it.

🔋 Dark Wallpaper Battery Calculator
Estimate how much battery a darker wallpaper really saves on your AMOLED phone — with the assumptions shown, not hidden.
🎨 Colour Palette Extractor
Drop in any image and pull out its dominant colours as hex and HSL, with a suggested Material You accent.
📱 Wallpaper Preview Mockup
See how a picture looks behind a lock-screen clock or a home-screen icon grid before you commit to it.
📊 Phone Display Database
A sortable, searchable table of popular phone screens — panel type, resolution, PPI, refresh rate, brightness and PWM.
🧭 Wallpaper Theme Finder
Six quick questions that point you at the wallpaper theme — and the app — that best matches your taste.

Why these tools exist

Most "wallpaper tools" online are thin wrappers around an upload form that ships your photo to a server. These don't. Each one is a single page of HTML and JavaScript that does its work locally — the battery calculator is just arithmetic, the palette extractor and the preview read your image through the browser's canvas without sending it anywhere, and the display database is a static table you can sort and filter.

They're meant as companions to the writing, not replacements for it. If a number from the battery calculator surprises you, the reasoning behind it is laid out in Why Dark Wallpapers Save Battery on AMOLED. If the palette extractor makes you curious about why certain colours work behind icons, that's the subject of the colour-theory guide. The tools give you the quick answer; the articles explain it.

Using them together

Individually each tool answers one narrow question, but run in sequence they cover most of the decision of whether a particular image will actually work on your phone. A reasonable order:

  1. Start with your screen. Look your phone up in the display database to find its panel type and resolution. Whether it's OLED or LCD decides how much a dark image is worth to you; the resolution and aspect ratio decide what shape the image needs to be. If those terms are unfamiliar, the display guide covers them.
  2. Check the crop before anything else. Drop the picture into the preview mockup and look at where the lock-screen clock and the icon grid fall. This is the step that eliminates most candidates — an image whose subject sits directly behind the clock isn't going to improve later. Sizing and cropping in more depth is covered in the resolution and aspect ratio article.
  3. See what it does to your system colours. Run the survivors through the palette extractor to find out what accent colour Android is likely to derive from each one. Two images that look similar can produce very different interface palettes.
  4. Then, if battery is the point, quantify it. The battery calculator will tell you what a darker choice is worth on your panel — usually a smaller number than people expect, which is worth knowing before you pick a wallpaper you don't like for a saving that isn't there.

If you don't have a candidate image yet and just want a direction, the theme finder is the place to start instead — six questions, and it points at the theme and the app most likely to suit you.